I bought shares in high street baker Greggs in November 2012 when it was in the midst of a restructuring programme, investing to strengthen the business and planning to open more than 120 stores that year.

Of course, that held back profit in the short term, but I liked the measures the firm was taking to improve its business, such as closing less profitable stores and opening them in better locations, including in transport hubs where there is better footfall and the opportunity for higher margins.

By keeping its popular format but improving efficiency, Greggs has cut costs and seen explosive profit growth. I bought shares at 478p and they are now 1011p.

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Back in 2014 and 2015, most of the UK supermarkets were going through a rough patch and I thought that in time they would all recover.

But sticking with Tesco turned out to be a mistake.

What I did not foresee was the extent of the assets the firm would write off – at £5.9billion they were so much bigger than anyone expected and it wiped out almost five years of profits, as well as undermining the balance sheet.

It was one of the largest losses in UK corporate history – the supermarket lost 50p per cent of its value in a year.

I had first bought shares in 2006 at 318p and I didn’t start selling until 2015 when they had fallen to 246p.